| Project/Area Number |
02557055
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Orthopaedic surgery
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| Research Institution | Hokkaido University |
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Principal Investigator |
KANEDA Kiyoshi Hokkaido University School of Medicine, Department of Orthopaedic Surgery, Professor and Chairman, 医学部, 教授 (60000957)
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| Co-Investigator(Kenkyū-buntansha) |
SHIBUYA Takehiro Nippon Electric Glass Co., Biomaterial Development Department, Director, 生体材料開発室, 室長
NISHIMURA Takumi Tohkai Rubber Industry Co., New Technology Development Department, Director, NT開発室, 室長
TADANO Shigeru Hokkaido University, Faculty of Engineering, Department of Mechanical Engineerin, 工学部, 教授 (50175444)
ISHIKAWA Hiromasa Hokkaido University, Faculty of Engineering, Department of Mechanical Engineerin, 工学部, 教授 (80001212)
ASANO Satoshi Hokkaido University School of Medicine, Department of Orthopaedic Surgery, Instr, 医学部・附属病院, 助手 (00212481)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥18,000,000 (Direct Cost: ¥18,000,000)
Fiscal Year 1992: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1991: ¥7,600,000 (Direct Cost: ¥7,600,000)
Fiscal Year 1990: ¥8,000,000 (Direct Cost: ¥8,000,000)
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| Keywords | human lumbar intervertebral disc / artificial intervertebral disc / artificial nucleus pulposus / bioactive ceramics / biocompatible elastomer |
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| Research Abstract |
(1) Evaluation of the mechanical properties of the human L4-5 functional spinal unit during cyclic loading : Cyclic axial compression-tension tests and cyclic torsional tests were performed on ten fresh human L4-5 functional spinal units to investigate the structural effects of the posterior elements of L4-5 functional spinal units.
The stiffness of the functional spinal unit increased with increase of displacement under every loading, This was same in the intact functional spinal units and the functional spinal units after removal each posterior element, respectively. All the posterior elements contributed to the compressive, tensile, and torsional stiffness of L4-5 functional spinal units. The apophyseal joints had a significant effect on the compressive and torsional stiffness. The effect of the apophyseal joints on the torsional stiffness became greater according to the extent of displacement, whereas their effect on the compressive stiffness was constant. The posterior ligaments (s
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upraspinous and interspinous ligaments) had a significant effect on the tensile stiffness.
(2) Evaluation of the mechanical properties of the human L4-5 disc during cyclic loading : Ten fresh human L4-5 disc-body units (DBUs) were examined for investigation of the relationship between the stiffness properties of L4-5 intervertebral disc and the displacement by cyclic compression-tension and torsion tests. The effects of an injury to the anulus fibrosus, nucleotomy and the filling-up of the denucleated space with silicone elastomer on the stiffness properties of L4-5 disc were also investigated.
The stiffness of L4-5 intervertebral disc increased with the increase of displacement in every type of loading, In each type of loading, the stiffness of the intervertebral disc after nucleotomy decreased significantly in every region of displacement. The torsional stiffness was restored significantly by the filling-up of the denucleated space with silicone elastomer. However, there was little restoration of both the compressive and tensile stiffness.
(3) Structural design of an artificial intervertebral disc : A new artificial intervertebral disc is proposed to reconstruct the stability and mobility of a human functional spinal unit. The geometry and the structure of the artificial intervertebral disc were designed by the computer simulation at 3D-FEM, as the compressive and the torsional stiffness of this model agree with the stiffness of cadaveric lumbar discs.
Consequently, the proposed model consists of two bioactive ceramic plates and intervenient substructure made from rubber-like materials. Glass-ceramic containing apatite and wollastonite was chosen as a material for the plates which come into contact with the bone, because this material is able to form a strong chemical bond with the osseous tissue. Elastic materials of medical grade in the substructure between two plates were selected, as a the artificial disc has the same stiffness properties with a cadaveric lumbar disc. Less
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